1. Field of the Invention
This invention relates to slurry pumps.
More particularly, this invention relates to modular centrifugal coal slurry pumps which may be stacked in series, limited only by the torque capacity of the pump drive unit.
2. Description of the Prior Art
Multiple pumps on a common shaft are well known in the prior art. For example, U.S. Pat. No. 1,020,161 describes a multiplicity of ganged pumps which are driven by a single, solid shaft extending through all of the individual pumps supported by bearing stands. The stackup of pumps are driven by an electric motor positioned at one end of the line of pumps. The foregoing pump arrangement is disadvantaged in that no single pump can be replaced without disassembly of the entire multiple-pump stackup.
U.S. Pat. No. Re. 28,540 describes a composite knockdown pump wherein the multiple pump assembly is essentially a multistage pump consisting of a plurality of pumps mounted to a common base and driven by a common shaft similar to the foregoing patent. Individual pump stages cannot be replaced without the disassembly of the multiple unit and the removal of the common shaft.
With an increase in the use of coal to fulfill our energy needs, the need to transport the coal is increasingly important. Therefore, pipelines carrying slurries of coal particles will be used extensively. Since coal slurry particles carried in a stream of liquid are abrasive, various pumping stations along the pipeline will require constant maintenance. By utilizing pump modules that may be easily coupled together for replacement purposes instead of a multistation pumping unit where failure of any one pump station will shut down the entire pipeline, the instant modular unit may be easily replaced with a minimum shutdown time. None of the foregoing prior art patents describe or teach a means to easily replace or repair a pumping station during operation. This invention goes beyond the prior art in that there is not a single drive shaft that goes through all of the pumping units--rather each modular pump may be disengaged from the stackup of modular units without removal of a single drive shaft. A self-centering coupling device associated with each of the modular pump units allows for self-alignment without a great deal of skill by the installer.
Therefore, an advantage over the prior art is the ability to remove one or more of the modular pump units from a drive line without removing a solitary drive line that drives all of the pumps.
Still another advantage over the prior art is the self-aligning centering feature of the coupling unit between the modular pump units.
Thus, it is an object of this invention to provide multiple modular pumping units that may be removed from a drive line without disturbing any of the other modular units within the pump stackup.
More specifically, it is an object of this invention to provide a modular unit which is a high-temperature centrifugal coal slurry pump with a self-centering coupling that may be easily installed or removed from a stackup of multiple modular pumping units without disturbing any of the other modular pumping units.